Printing telegraph apparatus



PRINTING TELEGRAPH APPARATUS Filed May 4, 1956 2 Sheets-Sheet 1 FIG. I87 I84 INVENTOR HOWARD L. KRUM CARL W. SWAN Nov. 21, 1939.

H. L. KRUM ET AL PRINTING TELEGRAPH APPARATUS Filed May 4, 193

6 2 Sheets-Sheet 2 FIG. 6

FIG. 5

FIG-2 9. ATTORN EY FIG. 4

INVENTOR HOWARD 1.. KRUM CARL w. SWAN Patented Nov. 21, 1939 PRINTINGTELEGRAPH APPARATUS Howard 1.. Krum, Kenilworth, and our w.' Swan,Chicago, 111., assignors to Teletype Corporation, Chicago, 111., a.corporation of Delaware - Application May 4, 1936, Serial No. 11,194

' 11 Claims. (.01. 191-53) This invention relates to printing telegraphapparatus and particularly to apparatus for recording messages.

, An object of the invention is to provide a type wheel capable ofefiecting print which em-' bodies all the desirable characteristics oftype bar printing.

A further object is to provide a type wheel having a plurality of setsof movable character elements arranged to be moved individually toeffect printing.

The invention features type pallets having shanks extending inwardlyradially of thetype wheel to be individually engaged by a printhafnl6mer.- The type wheel is featured in a new and extremelysimple'page printing telegraph receiver.

which, due to the characteristics ofthe type wheel, is capable ofproducing clear and legible multiple carbon copies.

Briefly, the printing telegraph'apparatus for which the type wheel inaccordance with. the invention has been particularly developed,comprises a typing unit removably mounted on a keyboard mechanism whichcarries a permutation code transmitting mechanism. Thetyping unitcomprises a single magnet selector which is articulated to a permutationcode disc selector, the discs of which are adapted to be setpermutatively in accordance with signals received by the single magnetselector. When permutatively positioned the code discs select one of aplurality of stop pins and permit it to be positioned in the path of anarm carried by a rotatable shaft, which is motor driven through afriction clutch and on which a type wheel is mounted. The type wheelthus may be stopped in various angular positions in accordance with theselection of stop pins. A

rotatable page width paper platen is mounted 40 in alignment with thetype wheel in a reciprocable carriage mounted on a foundation portion ofthe typing unit and arranged to be moved step by step by power mechanismto effect spacing and to be returned to line beginning position by theenergy stored in a spring.

- The single magnet selector mechanism includes a cam barrel assemblywhich is frictionally connected to a power driven shaft to be rotatedthereby and which controls the operation of the selector mechanism. Thelast mentioned power driven shaft also includes a set of operating camsmounted on a sleeve or bushing in fixed angular relation with respect toeach other and adapted to be driven -by the shaft through a positiveclutch mechanism in which drivingconnection member.

is established under the control of the selector cam barrel and which isdisengaged automatically at the conclusion of a single revolution of theoperating cams. One of the cams is efiective to operate a striker memberwhich delivers a blow .6 to a lever to which is connected a print hammerdisposed interiorly of the type wheel at the inner end of operatingshanks of character carrying elements mounted in the type wheel. Theblowwhich is delivered by the striker member is com- 10 municatedthrough the print hammer to the shank of a character element which isthus. causedtobe reciprocated. toward the printing platen. Another camincluded in the operating cam assembly operates carriage spacing mecha-'l6 nism and also performs certain necessary stuntsor functions. A thirdcam operates a transferball through the medium of which a selectionestablished in thesingle magnet selector as a result of the reception ofa code combination o is transferred to the discs of the code discseleclector mechanisms.

The type wheel comprises a radially slotted annular member whichreceives and slidably sup- 25 ports the shanks of type pallets havingflat faces disposed about the periphery of the annular Type characterelements are carried by the type pallet faces.- The type pallets arearranged in two annular rows and the shanks 30 of all pallets in a roware similarly notched to receive a tension spring which biases the typepallets to their innermost positions. A cover to which the hub of thetype wheel is secured is clamped by screws to the annular member and v 5closes'the tops of the slots therein. A floating ring preventsaccidental escapement of any of the type pallets from the slottedmember.

For a detailed description of the structure and operation of the variouselements, units, and combinations included in the typing unit, referenceshould be had to copending application of Albert H. Reiber, Serial'No.77,796,. filed on even date herewith, in which the entire printingtelegraph mechanism is disclosed in greater detail. 45

For a complete understanding of the present invention, reference may behad to the following description, in which only as much of the detailsof the typing unit as is necessary to afford a complete understanding ofthe inventionv has been in- 50 cluding the type wheel which constitutesthe present invention;

Fig. 2 is an exploded perspective view of the type wheel assembly;

Fig. 3 is a plan view, partly in section, of the type wheel assembly andrelated apparatus;

Fig. 4 is a vertical sectional view through the type wheel and relatedapparatus; and

Figs. 5, 6 and 7 are perspective views of type pallets.

Referring now to the drawings, in which corre-. sponding referencenumerals indicate identical parts in several views, and particularly toFig. 1, the reference numeral designates generally a keyboardtransmitter mechanism. For a detailed description of a keyboardtransmitter mechanism which may be employed as a part of the printingtelegraph apparatus to be described herein, reference may be had toUnited States Patent No. 1,595,472, granted August 10, 1926 to Howard L.Krum. In general, the keyboard transmitter mechanism ll comprises a basecasting l2 which pivotally supports at l3 a plurality of keylevers M.The keylevers l4 control the positioning of code bars (not shown) whichcorrespond in number to the selecting impulses in the particulartransmitting code which may be employed and to each of which isarticulated a lever l6 extending upwardly from within the base casting|2.

A transmitting cam shaft I1 is rotatably mounted in bearing supports 8carried by the base casting 2 and has fixed thereto a gear l9 which isdriven by a gear train comprising the gears 2| and 22 from a gear 23,the drive for which will be described later. The gear l9 has connectedthereto the driving portion of a tooth clutch 24, the driven portion ofwhich is connected to a cam sleeve 26. The driven portion of clutch 24is urgedby spring thrust into engagement with the driving portion and isnormally restrained from engagement therewith by a clutch throwout lever2! which is withdrawn from restraining engagement with the drivenportion of the clutch, by linkage not completely shown, when any one ofthe keylevers I4 is actuated.

The cam sleeve 26 carries a plurality of transmitting cams 28 each ofwhich includes a notch 29. A transmitting bell crank lever 3| ispivotally mounted in alignment with each of the cams 28 and each lever3| hasan arminot shown) which carries a cam follower (also not shown)for following the particular cam 28 with which the lever is aligned. Thecam follower of each of the transmitting bell crank levers 3| tends todrop into the notch 29 in its associated camwhen the notch is presentedto the follower but the pivoted levers l6 are effective when they occupycertain positions to block the cam follower arms of the bell cranklevers 3| to prevent the cam followers from dropping into the notches29. It will thus be apparent that as the cams 28 rotate, certain of thebell crank levers 3| will be permitted to rock and others will becranklever is rocked and an open circuit con- .unit to be describedhereinafter, so that marking and spacing impulses may be set up by theseveral contacts 32 in accordance with the positioning of the levers It.A knife edge 33 is carried by a pivoted bail 34 which has an arm 36provided at its outer end with a follower roller 3'| which follows a cam38 carried by the cam sleeve 26. The knife edge 33 drops into blockingengagement with lugs39 carried by the levers l6 when the cam barrel 26rotates, to prevent accidental shifting of the levers l6 while a codecombination is being transmitted.

The typing unit or receiving portion is designated generally by thereference numeral 4| and is removably mounted on the base casting |2 bysuitable bolts, not shown. The foundation .of the typing unit 4|consists of two castings upon which all of the receiving mechanism ismounted. One of the castings is designated 42 and extends from front torear of the base casting |2 .substantially parallel with thetransmitting cam shaft H. The other casting designated 43, is alsomounted on-the base casting I2 and extends across the base casting l2near the rear end thereof, substantially at right angles to the casting42. I

The casting 42 has secured thereto, bearing blocks 46 in which isrotatably mounted a vertical shaft which carries previously mentionedgear 23 and other mechanisms to be identified later. The gear 23 isfixed to the vertical shaft and is arranged to be continuously drivenfrom the rotor shaft of an operating motor not shown. It will be notedthat no reference character has been applied to the shaft upon which thegear 23 is mounted, the reason for this being that in Fig. 1 the shaftis concealed by the various elements mounted upon it. In addition to thegear 23 by which it is driven, the unseen shaft has fixed thereto thedriving portion 41 of a tooth clutch 48 and the spaced discs 49.

The discs 49 are adapted to drive a selector cam barrel 5| which isprovided at its opposite ends with discs 52. Friction discs 53 aredisposed between the discs 49 and 52, and the cam barrel 5|, discs 52,and friction discs 53 are confined between discs 49 under pressure sothat the cam barrel 5| when not under restraint is rotated by the discs49 fixed to the unseen shaft.

The cam barrel 5| constitutes an element of a. single magnet selectorindicated generally by the reference numeral 56. The selector mechanism56 may be constructed in accordance with the teachings of United. StatesPatent No. 1,937,376 granted November 28, 1933 to Walter J. Zenner. Theselector mechanism 56 comprises a plate 51 mounted on the casting 42 andhaving an aperture 58 through which the selector cam barrel 5| extends.The plate 5-! has mounted thereon a selector magnet 59 to which incomingsignal impulses are applied and which, with the cooperation of the cambarrel 5| having helically arranged cam projections controls theoperation of a sword-and-T lever selector assembly 63, also completelydescribed in said Walter J. Zenner patent, to effect the permutativesetting of lever arms 64 in accordance with impulses applied to theselector magnet 59.

- The lever arms 64 are provided at their outer 'ends with prongs 6.6between which are confined disc-like portions 61 of transfer bell cranklevers 68. The bell crank levers 68 are pivotally mounted at 69 and areprovided at the outer ends of their arms H with disc-like portions 12disposed in notches formed in permutation. code discs of a permutationcode disc selector indicated generally by the reference numeral 13.

tor comprises upper and lower spaced discs 16 and 11 respectively, whichgives a plurality of open slots 18radially arranged. The slots in thedisc 11 are concealed, in Fig. 1, by selectable stop pins 19 extendingfrom the lower disc 11 to the upper disc 16. The stop pins are formedwith loops 8| at their lower ends dis-' posed in the slots in the disc11,- and a garter spring 82 surrounds the pins 19 just above their loopportions BI and maintains them in their proper positions. The pins 19are of suflicient length to extend above the upper disc 16.

Below the upper disc 16 are rotatably mounted a plurality of code discs15 (Fig. 4) individually aligned with the transfer levers 68 andprovided, as previously stated, with notches which receive the disc-likeportions-12 of transfer bell crank lever arms H. The code discs areprovided with permutation code notches in the peripheries thereof, sothat for each permutative setting of the code discs onecomplete'alignment of notches shall be effected. When an alignment ofcode notches is thus effected, such alignment is presented oppositeone'of the selectable stop pins 19,

which pivots about its point of engagement with the disc 11, thus movingits upper end inwardly within one of the notches 18 and into the path ofa stop arm 83 fixed to a shaft 84 rotatably mounted coaxially of thecode disc selector mechanism 13. The shaft 84 is kept under constanttorque from the previously mentioned driving motor (not shown) through afriction clutch and suitable gearing (also not shown). When one of thestop pins 19 enters the path of the stop arm 83, the latter rotates intoengagement with the selected pin 19 and is thereby stopped to present aselected portion of a type wheel 88, the structural details of whichwill be described later, carried by shaft 84 near the top thereof anddriven therefrom, to a rotatable printing platen 81 carried by acarriage 88. The carriage 88 is recipe rocably mounted at the top offrame casting 43 and is urged to its right-hand position by a carriagereturn spring contained within a drum 89 which is engaged by one end ofa belt 9 I, the other end of which is connected tocarriage 88. Suit ablemechanisms for spacing the carriage and for performing line feed andcarriage return operations are provided and although not shown herein,are completely shown and described in the above mentionedcopending'application.

Above the code disc selector 13 and adjacent to the type wheel 86 isdisposed a feed mechanism for an inked printing ribbon, such as theinked ribbons employed in typewriters. The feed mechanism includes aplate 92, removably sup-.

ported above the code disc selector mechanism, which rotatably supportspins 93. The pins have secured thereto, below the plate 92, feedratchets 94, and above the plate'92 means (not shown) for engaging anddriving the ribbon spools 96 1 mounted on the pins 93. The plate 92 haspivotally mounted thereon a lever 91 which has at its left-hand end apivot pin 98 on which is pivotally mounted aratchet feed pawl 99 whichis adapted to engage either of the ratchets 94, depending upon thedirection in which the ribbon is to be fed, and rotate the ratchet, asthe lever 91 is rocked clockwise, to wind the ribbon on one spool,drawing it from the other spool. The right-hand end of operating lever91 enters a slot IIII in a link I92 which is pivotally mounted at I83 ona power actuated lever I96 pivotally mounted at I01 to a bracket I08secured to the frame casting 42.

Referring again to the tooth clutch 48, which is carried by the'selectorcam barrel shaft, the driven portion III is spring urged by spring 2'toward the driving portion 41 and is restrained from engagementtherewith by a clutch throw- Connected to the clutch throw-out lever H3is a lever arm I I6 disposed adjacent to the cam barrel to be actuatedby a cam projection thereon to effect withdrawal of the throw-out leverfrom out lever II3 pivotally mounted on a shaft I I4.

restraining engagement with the driven portion,

III. of the clutch 48.

The driven portion I II of the tooth clutch 48 is connected to drive asleeve I I1 which has fixed theretocams H8 and H9. Cam II8 isengaged bya cam follower roller I2I carried by a lever I22 pivotally mountedonshaft I23. Lever I24 also pivotally mounted on shaft I23 is connected atI25 to cam follower lever I22, and engages the ribbon feed mechanismoperating lever I06 to impart counterclockwise rotation thereto whenlevers I22 and I24 are rotated counterclockwise by the action of cam II8on cam follower I2I. Lever I24 carries pivot pin I26 to which arearticulated function performing bars I21 and carriage spacing pawl I28.

Above the cam' I I8 is box cam II 9 which is provided with cam grooveI29. Pivotally mounted on shaft I23 is a lever I3I which has a camfollower (not shown) disposed in the groove I29 in cam II9 to beactuated by an ofiset (not shown) therein. Lever I3I is arranged to berotated counterclockwise by cam H9, and has articulated thereto areciprocable bar I32 which is provided with an abutment I33. A strikermember I34 pivotally mounted at I38 has an arm, I31 disposed in the pathof abutment I33.

In Fig. 2 is shown an exploded view of the type wheel assembly 88. Thefoundation of the assembly is an annulus I4I having a groove I42 ofconstant depth and rectangular cross section in the periphery thereof,whereby upper and lower a circumference equal to that at the base ofgroove I42, whereby the flat rings would constitute flanges defining agroove. However, in

the embodiment shown in Figs. 2 and 4, the flanges are produced byforming the peripheral groove in an annulus having an outside diameterequal to that of the flanges I43 and I44. Radial .slots I48 are cutthrough the upper flange I43, through the annular wall'at the base ofthe groove I42,'and partially through the lower flange I44. The slotsI48 equal in number the possible permutation code combinations in thecode upon which the transmitting and receiving mechanism shown in Fig. 1is intended to operate, and they are uniformly spaced throughout all buta small angular portion of the member I4 I. In the small angular portionwhich is not slotted, the flanges are provided with a rectangular recessor keyway I41. In radial alignment with the recess I41 the flange I43 isprovided with a cylindrical aperture I48 extending therethrough. Theflange I44 is provided in the upper face thereof with a cylindricalrecess I49 coaxial with the aperture I48. The slotted flange I43 isprovided with tapped holes I5I.

The slots I46 are intended to receive and slidably support-and guidetype pallets I52, I63 and 203 shown in Figs. 2 to '7. As shown in Fig.'I, the type pallet I52 comprises a type carrying face I53 from the rearof which extends a thin flat shank I54. The shank I54 enters one of theslots I46 and is guided in the vertical portion at the base of thegroove 42 as well as in the horizontal portion in the flange I44. Eachof the type pallets I52 which is adapted to seat at the bottom of a slotI46 is provided at the top of the shank thereof with a notch I56, and acoiled wire tension spring I51 seats in the recesses I56 and extendsaround all the shanks I54 of the type pallets I52 and has hooks I58 atthe ends thereof engaging a cylindrical retaining pin I59, which isinserted in the grooved annulus I4I through the cylindrical aperture I48in flange I43 thereof, and which seats in the cylindrical recess I49 inflange I44 as shown in Fig. 4. The relationship between the depth of thegroove I42 and, the distance of theinner end of type pallet shank notchI56 from the inner surface of the type carrying face I53 is such thatthe notch I56 is entirely within the groove I42 even when the innersurface of the face I53 abuts the flange I44. It will be apparent fromthis that the spring I51 is seated in the notches I56 within the grooveI42 and urges the type pallets inwardly radially of the grooved annulusI4I so that the inner surfaces of type carrying faces I53 are urged intoabutment with the flange I44. It may be observed, by reference to Fig.3, that the type pallet shanks I54 are of sufficient length to extendinteriorly of the annulus I4I.

Directly above the spring I51 there is disposed a split ring I6I whichrests on the spring I51 and is of suflicient thickness to extend abovethe upper edge of the shank I54 a. distance equal to the extent to whichthe ring enters the notch I56 therein. The periphery of the ring I6I isdisposed adjacent tothe shoulder I62 in the shank of each of the typepallets I52. The ring I6I extends outside of the pin I59 and restsloosely or floatingly upon the spring I51 and within the notches I56 inthe type pallet shanks I54.

Above each of the type pallets I52 there is disposed in the slots I46 atype pallet I63 similar to the type pallets I52 except that the'typefaces I64 carry different characters than do the type faces I53, and thenotches I66 in the shanks I61 open downwardly instead of upwardly. Aspring I68 similar to the spring I51 and similarly engaging the pin I59is seated in the notches I66 in the type pallet shanks I61 and urges theinner surfaces of the type carrying faces I64 into engagement with theflange I43. The spring I68 presses downwardly upon the split ring I6Iand retains it centered within the groove I42 of annulus MI. The shanksof type pallets I63 rest upon the shanks of pallets I52 and since, aspreviously stated, the ring I6I is of suflicient thickness to extendabove the upper edge of the type pallet shank I54, it manifestly extendsinto the notch I66 in shank I61 of type pallet I63.

A cover I1I for the grooved annulus I4I has an aperture in the centerthereof which receives the upper end of a hub member I12 which is fixedto the cover I1I in any convenient manner such as by upsetting as shownat I13 in Fig. 4. The cover I" is provided on the lower surface thereofwith radially extending ribs I14, equaling in width the slots I46 inannulus HI and spaced in accordance with the spacing of such slots. Atone point in its periphery the cover I1I is provided with a recess orkeyway I16 corresponding to the recesses or keyways I41 in the flangesI43 and I44. The cover I1I is adapted to seat on the upper face offlange I43 with the ribs I14 entering the slots I46 and with the recessor keyway I16 in alignment with the keyways I41. Clamping screws I11enter apertures I18 in the cover "I and engage the threaded aperturesI5I in flange I43 of annulus I4I to clamp the cover I1I securely to theflange I 43.

In this way a type wheel assembly is provided in which, as shown inFigs. 3 and 4, individual type pallets arrangedin rows about theperiphery of the type .wheel are retained in slots by springs I51 andI68, by split ring I6I and by cover "I. Suflicient clearance is providedbetween the ribs I14 and the type pallets I63 to provide freedom of thepallets I52 and I63 for sliding movement radially of the type wheel andwithin'the slots of the annulus I4I thereof, within the limits affordedby the annular retaining ring I6I The springs I51 and I68 urge the typepallets to their innermost positions and the floating ring I6I preventsaccidental displacement of the type pallets from the type wheelstructure in the event that one of the tension springs should becomebroken and no longer maintain the type pallets under tension.

As shown in Fig. 4, the type wheel shaft 84 is provided at its upper endwith a reduced portion I8I whereby there is provided a shoulder I82. Thehub I12 isadapted to be mounted upon the reduced portion I8I of the typewheel shaft I84 with suflicient freedom to be slidable with respectthereto and to seat, in its" lowermost position, against the shoulderI82. An arm I83 is keyed to the type wheel shaft 84 at the upper endthereof and the arm I83 supports an arm I 84 which is provided withslots I86 through which pass clamping screws I81 which threadedly engagethe arm I83 and thus adjustably clamp arm I84 to arm I83. Arm I84 isprovided at its outer end with depending arm I88 which enters therecesses or keyways I16 and I41 in the cover I and annulus I4Irespectively. The arms I83, I84, and I88 serve as driving connectionbetween the type wheel shaft 84 and the type wheel 86.

A print hammer I9I is pivotally mounted at I92 above the code discselector 13 between the type wheel shaft 84 and the platen 81 and facingthe latter. The print hammer I9I has integral therewith a bail memberI93 which extends rightwardly from the print hammer I9l, as viewed inFig. 3, and has integral therewith, at the righthand end thereof anoperating lever I94 (Figs-1 and 3) pivotally mounted at I96 coaxiallywith respect to the pivotal mounting I92. The lever I94 carries aresilient impact receiving member I91 (Figs. 1 and 3) which isdisposedin the path of the outer end of striker member I34. The impact receivingmember I91 is adapted to be struck a sharp blow by the strikerrnemberI34, when the wise, as shown in Fig. 1, and 'thus rotate the printhammer I9l clockwise, as viewed in Fig. 4, to reciprocate the typepallet then in alignment with the print hammer 'I9l to effect printingby operation between the platen 81 and the type face 'of one of the typepallets I52 or I63.

It will be observed that in Fig. 4, a type pallet I63 of the upper rowof typepallets is aligned with the print hammer HI and the printingposition of the platen, due to the fact that the hub I12 which supportsthe type wheel 86 is in its lowermost position. At its lower end, thehub I82 is engaged by a horizontal arm I98 of a shifter frame I99located at the right side of the typing unit (Fig. 1) and arranged to belifted and lowered by the operation of shift bell cranks 20I and 202through connections fully described in the hereinbefore mentionedcopending application. When the sh'ifter'fr'ame I99 is lifted by theoperation of the 'bell crank lever 20I, the type pallets I52 in thelower row are brought into alignment with the head of print hammer I9Iand in alignment with the printing position of platen 81. Manifestly anytype pallet in either row may be brought into operative alignment withthe print hammer by shifting the type wheel to the proper level andstopping the type Wheel in a particular position as determined by thecooperation of the stop arm'83 .selectable stop pin 19. When the typewheel is shifted upwardly or downwardly on the shaft 84, the keywayrecesses I41 and I16 slide on type wheel driving arm I86.

It will be noted that there is shown in Fig. 6

a type pallet difiering from those shown in Figs. 5 and 7 in that theface thereof carries no character by which printing canv be effected andthe shank thereof is shorter than the shanks I54 and I61. The blank ordummy pallets 203 shown in Figs. 3 and 6 are employed in those stoppositions of the type wheel at which the printing of acharacter is notdesired; for example, functions such as shift, unshift, carriage return,line feed, etc. are functions which must be performed under certainoperating conditions and it is usually not desirable to print characterswhen such functions are performed. It is fully set forth in thecopending application that the code disc selector I3 selects a stop pinI9 for functions as well as for characters and that the type wheel isbrought to a stop at certain positions corresponding to the functionselections. In order that printing may be avoided when the function isperformed, the short shanked pallets 203 are provided,-which the print'hammer I9I will not reciprocate a suflicient distance to bring thepallet into cooperation with the platen 81 and which carries nocharacter to be recorded. With this arrangement it is not necessary todisable the striker member I34, the lever I94, or the print hammer I 9Iwhen afunction is performed.

Referring particularly to Fig. 1 for a descrip tion of the operation ofthe typing unit 4|, attention is directed first to the selectormechanism 56, the selector magnet 59 of which receives signalingimpulses from a suitable telegraph circuit and with the cooperation ofcam barrel 5|, which is released for rotation at the beginning of eachgroup of code impulses, se s the sword-and-T selector mechanism 63 bymeans of the selector lever 62. The setting of T-levers 64 in accordancewith received code impulses is transmitted to the code discs 15, throughthe transfer levers 68, and a particular stop pin 19 corresponding tothe with a particular code signal received by the selector magnet 59enters the path of type wheel stop arm 83. .Type wheel shaft 84 ispermitted to rotate until it is stopped by engagement of the stop arm 83with the selected stop pin 19. In this manner a particular type palletI52 or I63, depending upon the previously established shift or unshiftcondialignment with the print hammer I9I.

At a predetermined point in the cycle of operation of the selector cambarrel 5|, the clutch throwout lever H3 is tripped by lever H6 and camsleeve II! is set in rotation. The sleeve 1 imparts rotation to the camsH9 and H8. As cam II 9 rotates, itsfollower (not shown) is tion of thetype wheel, is brought into operative operated to cause counterclockwiserocking of lever I 3| to which is articulated bar I 32. Abutment I33carried by bar I32 rotates striker member I34 counterclockwise throughits engagement with lever arm I31 thereof, and thus a sharp blow isimparted to impact receiving member I 91. The blow is transmittedthrough lever I94, bail I93, and print hammer I9I to the particular typepallet which is aligned with the hammer to cause it to be propelledtoward the printing platen 81 to effect printing on paper which may becarried by the platen. The character printing movement of the typepallets I52 or I63 is effected in 0pposition to their retaining springsI51 or I68 which are operative after printing of the character has beeneffected to restore the type pallets to their unoperated positions inabutment with the flanges I43 and I44.

In the event that the selected stop pin I9 corresponds to a, function tobe performed instead of to a character to be printed, one of the dummytype pallets 203 may be aligned with the print hammer I9I in the stopposition of the type wheel 86, and since the dummy pallet 203 carries noprinting element, and since its shank isv shorter than those of thecharacter carrying type pallets,

it will not be actuated to produce any marking upon the paper carried bythe printing platen.

It should be noted particularly that by means of the type Wheelstructure described herein, including the individual type elements,great flexibility of arrangement is afforded. The character printingelements may be arranged in any desired order in either the upper or thelower position particular arrangementof type pallets may be readilyconverted to conform to a different standard merely by rearranging the,type pallets within the type wheel structure or by substituting othertype pallets.

It will be understood that the invention is not limited to the provisionof dummy type pallets as shown in Fig. 6 in those positions whichcorrespond to function selections. It may, under certain circumstances,be desirable to effect the printing of a character simultaneously with aperformance of a function in order that there may be permanent record ofthe performance of that function and in such cases type pallets inaccordance with Figs. 5 or. 7 and provided with any desired symbol maybe employed.

The springs I51 and I68 engage all of the type spring pallets in theparticular set with which each is associated, and thus yieldingly retainall of the type pallets in the set under uniform tension. The floatingring [BI is provided as a safety feature to prevent escape of the typepallets from the annulus MI and scattering of the pallets due tocentrifugal force should breakage of either of the springs I61 or I68occur.

Although a particular embodiment of the invention has been describedherein, it will be understood that the apparatus is capable of manymodifications and substitutions in the various elements and combinationsthereof within the scope of the appended claims.

What is claimed is:

1. In a type wheel mechanism, a plurality of individual type elements,single means for displaceably retaining certain of said type elements,other single means for limiting the displaceability of all of saidtype'elements, and means for selectively actuating any One of said typeelements.

2. In a type wheel mechanism, a plurality of individually movable typeelements arranged in circular formation, a spring arranged to engagecertain of said type elements, single means fordetermining a limit ofmovement for all of said type elements, and means for actuating saidtype elements individually against the tension of said 3. In a typewheel mechanism, an annular member having radial slots, a plurality oftype pallets having shanks slidably disposed in the slots, means forretaining the shanks in said slots for limited sliding movement therein,and a cover for said annular member .having radially extending ribsarranged to enter the slots in said annular member.

4. In a type wheel mechanism, a slotted retaining member, a plurality oftype members slidably retained in said member, a spring yieldinglyengaging a plurality of said type members, a floating member forlimiting the sliding movement of said type members, and means forselectively actuating said type elements individually.

5. In a type wheel mechanism, a slotted retaining member, a plurality oftype pellets having thin flat shanks slidably disposed in said member, atension spring yieldingly engaging the shanks of certain of said typepallets, means for selectively operating said type pallets, and afloating member for limiting the operative movement 01 said typepallets.

6. In a type wheel mechanism, a retaining member having radial slots, aplurality of type pallets having thin flat shanks slidably disposed inmutual frictional engagement in the slots in said member, the shanks ofsaid type pallets having notches, a tension spring disposed in thenotches of certain of said type pallets, and means for actuating saidtype pallets individually.

'7. In a type wheel mechanism, an annular member having radial slots, aplurality of type pallets slidably disposed in each of said slots, atension spring engaging each of the type pallets in a slot, means foroperating upon the type pallets in a slot individually, and single meansfor limiting movement of all of the type pallets in a slot.

8. In a type wheel mechanism, an annular member having radial slotstherein, a pair of type pallets slidablyvdisposed in each slot thereof,and

a floatingly mounted member for limiting the slidable movement of all ofsaid type pallets.

9. In a type wheel mechanism, a memb r aving radial slots, a pair oftype pallets disposed in each slot and having opposed notches therein,yieldable means for urging all of said type pallets toward the center ofsaid member, and single means entering the notches of all of said typepallets for retaining the pallets within said member.

10. In a type wheel mechanism, an annular member having radial slots anda peripheral groove, a circular row of individual type characterelements disposed about the periphery of said member and having shanksdisposed at the base of said slots and extending through said groove andtoward the center of said member, another circular row of individualtype character elements disposed about the periphery of said memberabove the first mentioned type character elements and having shankssimilarly extending through said groove and toward the center of saidmember, the shanks of'the first mentioned row of elements having notchesin the upper edges thereof aligned within the groove, the shanks of thesecond mentioned row of elements having notches in the lower edgesthereof in alignment with the notches of the first mentioned shanks, aspring conformed to a ring shape and disposed in the notches of thelower row of type character elements, a spring conformed to a ring shapeand disposed in the notches of the upper row of type character elements,a ring 'floatingly positioned by said springs and extending into thenotches of both rows of type character elements, and a cover secured tosaid annular member over the tops of the slots therein.

11. In a'printing telegraph apparatus, a type wheel including an annularmember having a plurality of radial slots, a peripheral row of characterelements having shanks slidably retained in said slots, a secondperipheral row of character elements having the shanks thereof slidableupon the shanks of the first mentioned row, and a floatingly mountedmember for limiting the slidable movement of all of said characterelements.

12. In a printing telegraph apparatus, a. type wheel including anannular member having a plurality of radial slots, a peripheral row ofcharacter elements having shanks slidably retained in said slots, asecond peripheral row of character elements having the shanks thereofslidable upon the shanks of the first mentioned row, and meanscooperating with the shanks of both rows of character elements forlimiting the slidable movement thereof. V

13. In a printing telegraph apparatus, a type wheel including an annularmember having a plurality of radial slots, a peripheral row of characterelements having shanks slidable in said slots, 2. second peripheral rowof character elements having the shanks thereof slidable within theslots upon the shanks of the first mentioned row, and a cover plate forsaid member having radially extending ribs disposed in said slots.

14. In a type wheel mechanism, a retaining member having radial slots, aplurality of type pallets having thin flat shanks slidably disposed inmutual frictional engagement in the slots in said member. the shanks of'said type pallets having notches, tension springs disposed in thenotches of certain of said type pallets, means for holding said springsin their respective notches, and means for actuating said type palletsindividually.

15. In a type wheel mechanism, a retaining member having radial slots, aplurality of type member having radial slots therein, a pair of typepallets having confronting notches and slidably disposed in each slotthereof, tension means disposed in the notches of said type pallets. andmeans for holding said means in their respective notches.

17. In a type wheel mechanism, an annular member having radial slotstherein, a pair of type pallets having confronting notches and slidablydisposed in each slot thereof, tension means dis posed in the notches ofsaid type pallets, and means dually efl'ective for holding said means intheir respective notches and limiting the 'slidable 1 movement of all ofsaid typ pallets.

, HOWARD L. KRUM.

CARL W. SWAN.

